Download games may be cheap, but that doesn't mean they have to be demonstrably inferior to shop-bought ones: recent Xbox Live Arcade and PlayStation Network efforts like Braid, Limbo, ilomilo and Zeit2 have been deservedly showered with praise. Such games derive much of their appeal from offering gameplay which harks back to simpler retro days spruced up with the odd modern twist. Stacking takes a subtly different approach by harvesting the general ethos of old-school point-and-click adventure games (of which, with the likes of Monkey Island, Full Throttle and Grim Fandango, Double Fine proprietor Tim Schafer made some of the finest) and ripping out the static, 2D, single-path gameplay in favour of something more immediate and modern.

Stacking's general premise and art style are both utterly delightful. Set in a world populated by Russian dolls, apparently (and appositely) during the 1920s depression, you play Charlie Blackmore, the youngest and runtiest of a large family of chimney-sweeps. Times are bad, and Charlie's parents and siblings end up enslaved by the evil Baron, so Charlie heads to the train station, befriends a hobo called Levi and sets about rescuing them – plus the rest of the land from the Baron's dastardly yoke.

Visually, Stacking is sumptuous (unsurprisingly, given that it was conceived by Lee Petty, art director on Double Fine's Brutal Legend). Influences include silent movies (especially those of Charlie Chaplin), dioramas and dolls' houses. Because Charlie is so tiny, he can stack into the back of other dolls of incrementally increasing sizes. Each doll has a special skill, which might be a vigorous handshake, fixing mechanical objects, playing the violin, farting pot-pourri or delivering an uppercut. Charlie must use these abilities to solve puzzles.

As you may have guessed from the diversity of those abilities, Stacking's gameplay is gloriously whimsical and offbeat. But its cleverest aspect is that each puzzle has multiple solutions, and when you solve it once, you're told how many other solutions it has. So, crucially for a download game, it has loads of replay value. You can while away hours seeking out dolls you haven't met before, or performing Hi-Jinks: playing pranks such as a white-gloved slap on random dolls. There are sets of dolls to find, generally either particular families or dolls with similar abilities, like Adventurers: when you find them and stack them into each other, you're treated to a diorama-style mini-drama.

The puzzles themselves are often hilariously inventive – you might have to lure railway grandees from their cosy gentlemen's clubroom by stacking into a mechanic doll, dismantling a fan and using it as a means of invasion, flatulating into the fan and introducing a noxious atmosphere or using the hip-swinging Widow Chastity to seduce the doorman from his post. Schafer's games are known for their humour, and this is one of his funniest.

Stacking is right up there with the likes of Braid and Limbo as an absolute must-download. Merely toddling around its world is fun, and the fact that its gameplay is thoroughly distinctive is a bonus. If you know anyone who still believes that games are uniformly violent and brain-dead, Stacking will comprehensively disabuse them of that notion.